I looked into several, but eventually decided to select a lawyer to handle our wills. The online sites offered some ability to do some limited customization, but for the most part the language seemed very boilerplate. That may work for some, but we decided we needed some contingencies put into our wills that the sites could not handle. In IL, we can create a pet trust to care for any pets remaining after we both pass away ... none of the web sites were equipped to handle that.
If you just need a simple will with a few bequests, most online sites can handle that. If you want something more complex, I'd recommend talking to a lawyer.
We're glad we did. We're getting some additional forms drawn (financial and healthcare Power of Attorney) to take care of things if/when we can't care for ourselves. For everything we are having done, I think the final bill was close to $1,200 or so. Not cheap, but we know it was done right for our state.